Bottle

ABSTRACT

A container having a protruding, threaded neck portion and a screw on cap is disclosed. The container includes a pair of mating seating surfaces on the base of the cap and neck and sealing surfaces on the top of the neck and on the inside surface of the top of the cap. The sealing surfaces are adapted to engage in response to torque applied to the cap after said seating surfaces have been engaged.

llnited States Patent 1191 Baldwin et al.

[ 11 Dec. 31, 1974 [54] BOTTLE 3,339,773 9/1967 Stull 2l5/43 3, 2, 6 1 1Marsha" Glenn Baldwm, Weapon, 3331,3251 3113?; 23,131? iii/315 Conn;Gilbert Dwayne Miles, Ossiningy FOREIGN PATENTS OR APPLICATIONS 1 111522;? 11/12:? 9122:1111;-------'--------;;;;;; 212/1; York 1,101,3885/1954 France 215/43 22 Filed: Oct. 1 1972 968,767 3/1958 Germany 215/43[21] Appl- N05 298,656 Primary ExaminerWilliam I. Price AssistantExaminer-R0 E. Hart 52 11.5. c1. 215/329, 220/4 B Attorney, Agent. orFirm-Herbert Sylvester, q-; 151 1111. c1 B6511 41/04 Murray Grill, 14Kenneth Koch, q- [58] Field of Search 215/43, 44, 49 R, 11, II R,

215/11 A, 11 C, 329, 218; 220/4 B, 4 E, 39 R [57] ABSTRACT A containerhaving a protruding, threaded neck por- [56] References Clted tion and ascrew on cap is disclosed. The container in- UNITED STATES PATENTScludes a pair of mating seating surfaces on the base of 774,014 11/1904Wilson 215/44 the cap nd neck and sealing surfaces on the top of1,682,403 8/1928 Murray 220/4 B the neck and on the inside surface ofthe top of the ,152 9/1932 Sheaffer 215/43 R cap. The sealing surfacesare adapted to engage in reg ig l sponse to torque applied to the capafter said seating ry en er 1. 4 3,010,596 11/1961 Williams 215/43Surfaces have been engaged 3,027,034 3/1962 Christian 215/43 8 Claims, 4Drawing Figures f A 16 //,1// yam c I k I I 11 l l I 13 1O PAIENTEDBEBB1 IBM 3'. 857. 509

' sum 20F 2 BOTTLE The present invention pertains to containers for thepackaging of liquids such as light and heavy duty detergents, shampoos,etc. More specifically, the invention provides a container of thethermoformed type having an improved leak resistant threaded dispensingneck and screw-on cap.

Thermoformed bottles are characterized by a top and bottom portion thatare separately made and joined together by suitable means such as acircumferencially welded seam. Bottles of this type have been used topackage a variety of products, including powdered cleansers, yogurt,milk and juices. In recent years, their use has substantially increasedbecause of the attractive economics involved in employing suchcontainers.

Thermoformed containers are fabricated from two separate thermoplasticsheets of required thickness; each sheet forming, respectively the upperand lower portions of the container. Each sheet is heated and forcedinto the mold of a high speed thermoforming machine to produce thebottom and top halves of the container. The thermoformed parts comingout of the two forming machines, still attached to the sheet ofthermoplastic material, enter two trim presses that automatically trimthe sheets. The top and bottom halves are then dropped onto conveyorsand supplied to appropriate means for joining the two halves together.

Thermoformed halves can be joined together by various means includingspin-welding, heat-sealing, ultrasonic-sealing, solvent-sealing,adhesive-sealing and any other suitable process. In accordance with theinvention, it is preferred to utilize spinwelding. When the spin-weldingprocess is used, the top and bottom halves are supplied to aspin-welding apparatus after they are thermoformed.

The spin-welding is either a or -head rotary inside surface of the capand the top annular surface of the neck. To insure that an adequate sealis made at this point, a space is left between the base of the neck andthe bottom of the cap, i.e., the length of the neck is greater than theinside depth of the cap. Accordingly, when the cap is screwed on thereis nothing to prevent the top annular surface of the neck from seatingagainst unit. Machine size is dependent on volume requirements. The topand bottom halves are fed into holding mandrels by starwheels andrestricted from rotating within the mandrels either by vacuum or bymechanical means.

Seated within the mandrels, the two halves are held apart from eachother, with one half stationary while the other is rotated and broughtup to welding speed, typically from 2,000 to 5,000 RPM. The mandreldrive is then disengaged and the two halves are brought to-- The use ofthe thermoform process to make bottles the upper inside surface of thecap when torque is applied to the cap. Because of the deformable natureof the threaded neck of thermoformed bottles designed to accept ascrew-on cap, a leak-proof seal between the bottle and the cap isdifficult to obtain. When the cap is screwed on and seated, the appliedforces can deform the neck to the point where the seal between the capand neck is broken and the liquid contents of the bottle can escapeduring handling.

It is a primary advantage of the invention to provide an improvedleak-proof threaded neck/screw-on cap combination for use withdeformable, thin walled bottle necks, principally those of the:thermoformed type. A further advantage of the invention is the provisionof a plurality of seals between the threaded neck of the bottle and thescrew-on cap to insure leak-proof performance.

SUMMARY OF THE INVENTION In accordance with the invention, a threadednozzle neck is provided having an annular shoulder at its base and alength less than the inside depth of the screw-on cap to be used incombination therewith. The shoulder has an upper seating surfacedesigned to form a seal with the lower annular surface of the screw-oncap. Further, pursuant to the invention, the threaded neck, as measuredfrom the seating surface of the shoulder to the annular surface at itstop, is shorter than the inside depth of the screw-on cap as measuredfrom the annular seating surface at its base to the inside surface ofthe cap top. I

By providing the bottle of the invention with nozzle neck shorter thanthe depth of the cap, the bottom surface of the cap first seats againstthe annular surface of the neck shoulder. Further torque on the capafter it contacts the shoulder fully seats the base of the cap on theneck shoulder and creates longitudinal forces along the neck. Because ofthe thin wall thickness and deformable character of the neck, theapplied longitudinal forces result in elongation of the neck and seatingof the annular surface of the top of the nozzle neck against the topinside surface of the screw-on cap. Accordingly, the invention providesa dual sealing cap providing improved resistance to leakage for bottleshaving relatively thin nozzle necks and containing liquid products.

In further accordance with the invention, a thermoformed bottle having ascrew-on cap suitable for packaging liquid products such as light andheavy duty liquid detergents, shampoos, etc., is provided. The use of ascrew-on cap thermoformed container for packaging liquid products ofthis type has not been generally accepted because of the leakage problempresent when a conventional screw-on cap is used. in conjunction with athin walled deformable nozzle neck.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of acontainer according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawing, FIGS. 1and 2 show a thermoformed spin-welded container 1 having an integralprotruding threaded neck portion 2 adapted to accept screw-on cap 3. Thecontainer 1 is typically generally cylindrical in shap consisting ofthermoformed upper and lower portions 4 and 5. Portions 4 and 5 arejoined together by a spin-welded girth seam 6 to form a completecontainer. The bottom portion 5 of the container 1 includes afrusto-conical wall 7 of circular cross section and a bottom wall 8. Theupper portion of container 1 includes a side wall 9 of circular crosssection, threaded neck 2 and a sloping connecting portion 10 joiningside wall 9 and neck 2.

Pursuant to the invention, container 1 is fabricated from thermoplasticsheet material such as polyethylene, polypropylene, polyvinyl chloride,or any other suitable thermoplastic material, by the aforementionedthermoforming spin-welding techniques. Threaded neck 2 is usuallysomewhat thinner than the side walls 7 and 9 as a result of thethermoforming process and is normally quite deformable, having a wallthickness from about 0.01 to about 0.05 inch, typically from about 0.015to about 0.025 inch. Because of its deformable character and thin wall,neck 2 is capable of elongating a few hundreths of an inch whensubjected to longitudinal forces generated by applying torque topartially seated cap 3 in accordance with the invention. According to afurther specific aspect of the invention, the neck 2 is provided withthreads having a bellows configuration. The bellows threads function topermit uniform elongation upon the application of torque to thepartially seated cap 3 and provide a uniform wall thickness for neck 2.

Referring now to FIG. 3, the portion of a bottle 1 having a hollownozzle neck 2 and a continuous helical thread 11 disposed around itsperiphery and adapted to engage corresponding threads 12 disposed aroundthe interior circumference of screw-on cap 3 permitting cap 3 to bescrewed onto neck 2 is shown. A shoulder 13, having a seating surface14, is disposed about the base of neck 2.

Cap 3 includes a closed top end 15 having a seating surface 16 adaptedto seat against the annular seating flange 17 at the top of the neck 2as shown in FIG. 4, and an annular seating surface 18 at its base. Cap 3can also include an annular plug 19 extending from the top end 15 of thecap into the hollow nozzle neck 2 and contacting the inside periphery ofseating flange 17.

In accordance with the invention and as shown in FIG. 3, the normallength L. of the nozzle neck 2 is less, by the distance L than the depthof the screw cap, L

FIG. 3, shows the screw cap 3 screwed onto neck 2 to the point where thesurfaces 14 and 18 make contact. FIG. 4 shows the cap 3 fully seatedwith the nozzle neck 2 elongated an amount equal the distance L byfurther torque applied to cap 3 after it contacts surface 14 of shoulder13, so that seating surfaces 16 and 17 are joined under compressiveforces.

Further, the elongation of the neck during seating of the cap, inaccordance with the invention results in a resiliant lock between thethreads of the neck and cap. The aforementioned resiliant lock, which issimilar to a lockwasher effect, results in a removal torque less thanthe applicative torque for ease of opening the container while providingprotection against the cap loosening when jarred during shipping in theusual corrugated cartons. Surprisingly, the removal torque remainsconstant during shipping and warehousing conditions.

The invention provides a combination threaded container neck andscrew-on cap that is particularly advantageous for use with containershaving thin, deformable walls. The dimensional relationship between theneck and cap is such that a substantially leak-proof seal is obtained.In its preferred form, the invention provides a seal between the base ofthe cap and the neck and a secondary seal, formed by elongation of thenozzle neck in response to torque applied to the cap after the basesealing surfaces are in contact, between the top of the cap and neck.

We claim:

1. A container comprising a. a body portion,

b. a hollow open-ended cylindrical neck portion protruding from saidbody portion,

c. said neck portion having a first sealing surface disposed on its topsurface and a threaded exterior surface,

d. an annular shoulder disposed around said neck portion,

e. said shoulder being adjacent said body portion and having a firstseating surface lying in a plane transverse to the axis of said neckportion,

f. said neck portion having a predetermined height measured from saidfirst seating surface to said first sealing surface,

g. a cap member having a threaded inner surface adapted to engage thethreaded exterior surface of said neck portion,

h. said cap member having an open base end, a closed top end, and asecond sealing surface, adapted to engage said first sealing surface,disposed on the inner surface of said closed top end,

. said base end defining an annular second seating surface correspondingto said first seating surface,

j. said cap member having a predetermined depth, measured from saidsecond seating surface to said second sealing surface,

k. said predetermined height of said neck portion being less than thepredetermined depth of said cap member.

2. A container according to claim 1 wherein said neck portion is adaptedto elongate a distance substantially equal to the difference betweensaid predetermined depth and said predetermined height, in response totorque applied to said cap member after said first seating surfaceengages said second seating surface. i

3. Container according to claim 1, wherein said body portion comprises athermoplastic material.

4. Container according to claim 3, wherein said body portion comprisesupper and lower portions joined by a girth weld of said thermoplasticmaterial.

5. Container according to claim 3, wherein said nozzle neck is fromabout 0.01 and 0.05 inches in thickness.

6. In a container having a threaded nozzle dispensing neck, a screw-oncap, an annular shoulder adjacent the base of said neck for engaging thebase of said cap, a first sealing surface disposed in the inner topsurface of said cap, and a second sealing surface, adapted to engagesaid first sealing surface, disposed on the top surface of said neck,the improvement wherein the depth of said cap measured from its base tosaid first sealing inch.

1. A container comprising a. a body portion, b. a hollow open-endedcylindrical neck portion protruding from said body portion, c. said neckportion having a first sealing surface disposed on its top surface and athreaded exterior surface, d. an annular shoulder disposed around saidneck portion, e. said shoulder being adjacent said body portion andhaving a first seating surface lying in a plane transverse to the axisof said neck portion, f. said neck portion having a predetermined heightmeasured from said first seating surface to said first sealing surface,g. a cap member having a threaded inner surface adapted to engage thethreaded exterior surface of said neck portion, h. said cap memberhaving an open base end, a closed top end, and a second sealing surface,adapted to engage said first sealing surface, disposed on the innersurface of said closed top end, i. said base end defining an annularsecond seating surface corresponding to said first seating surface, j.said cap member having a predetermined depth, measured from said secondseating surface to said second sealing surface, k. said predeterminedheight of said neck portion being less than the predetermined depth ofsaid cap member.
 2. A container according to claim 1 wherein said neckportion is adapted to elongate a distance substantially equal to thedifference between said predetermined depth and said predeterminedheight, in response to torque applied to said cap member after saidfirst seating surface engages said second seating surface.
 3. Containeraccording to claim 1, wherein said body portion comprises athermoplastic material.
 4. Container according to claim 3, wherein saidbody portion comprises upper and lower portions joined by a girth weldof said thermoplastic material.
 5. Container according to claim 3,wherein said nozzle neck is from about 0.01 and 0.05 inches inthickness.
 6. In a container having a threaded nozzle dispensing neck, ascrew-on cap, an annular shoulder adjacent the base of said neck forengaging the base of said cap, a first sealing surface disposed in theinner top surface of said cap, and a second sealing surface, adapted toengage said first sealing surface, disposed on the top surface of saidneck, the improvement wherein the depth of said cap measured from itsbase to said first sealing surface is greater than the height of saidneck measured from said annular shoulder to said second sealing surface,said neck being adapted to elongate a sufficient amount to engage saidfirst sealing surface with said second sealing surface when torque isapplied to said cap after engaging said annular shoulder.
 7. Theimproved container of claim 6, wherein the base of said cap forms asubstantially liquid-tight seal against said annular shoulder.
 8. Theimproved container of claim 6, wherein said dispensing neck comprises athermoplastic material having a wall thickness from about 0.01 to about0.05 inch.